It wasn't clear from the article. What kind of wall did they hit?
https://news.ycombinator.com/item?id=18205837
I guess the majority of the damage was done by the large steel antennae it hit before the wall.
One takeoff I was on, the plane was vibrating like crazy, like I've never heard before but after a few minutes, it stopped and nothing happened!
https://ichef.bbci.co.uk/news/624/cpsprodpb/C99D/production/...